The present invention relates to a fuel feeding device for multi-cylinder internal combustion engines and, more particularly, to an electronically controlled fuel jetting device of the single point injection type in which fuel is supplied to such an engine through a single fuel jetting valve.
An average size of fuel particles produced by prior art fuel jetting devices was about 600.mu.. This degree of atomization was not sufficient to provide suitable fuel distributions and air-fuel ratios for all cylinders when only a single jet was used.
This was particularly true when the engine is cold, the results including misfiring and backfiring of the engine and other signs of reduced performance.
Previous attempts to correct such drawbacks by using a heater in combination with a flat bimetal strip were not completely successful as the bimetal was cooled by intake air inspired because it was located inside the intake passage. Attempts to use a wax device were hampered by the fact that the device could not be made small enough to be mounted on the intake manifold (which we will refer to as a "throttle body"). The accuracy of flow characteristics could not be made to be less than .+-.5%, which was not sufficient.
Prior Art devices were also often designed so that pressurized fuel flowed from a pressure regulator to a jet via metal or rubber tubing. This arrangement had several disadvantages, including difficulty in fabrication due to the complexity of the structure and the decreased reliability due to a number of connections involved.